Safety switch



May 10, 1932. J. J. DANTE l SAFETY swfrcH FledMay 25, 1929 2 Sheets-Sheet l Ill/11111114 fill 1NVENT0R Joseph J an ie ATTORNE May 10, 1932. J. 1 DANTE 1,857,711

SAFETY SWITCH Filed May 25, 1929 2 Sheets-Sheet 2 l NVENTOR J0 .9e/ah J. Dan e ATTORILJE PatentedMay 1o, 1932 UNITED STATES PATENT OFFICE JOSEPH JOHN DANTE, OF BANTAM, CONNECTICUT, ASSIGNOR TO THE TRUM'BULL-VAN- DERPOEL ELECTRIC MANUFACTURING COMPANY, A. CORPORATION OF DELAWARE SAFETY SWITCH.

Application le; May 25,

This invention relates to safety switches, vand more particularly to a safety switch enclosed within a casing, the cover of which is adapted to be locked in closed position as long as the switch remains closed.

One object of this invention is to provide an enclosed safety switch of the above nature having means for preventing closing of the switch when the cover is open, said means being released by the closing ot' the cover to ermit the switch to be closed.

A further object of the invention is to provide a device having a plunger mounted on the side of the casing, said plunger having a latch member adapted tobe rotated into lock ing engagement with a catch on the cover when the switch is moved to closed position.

A further object is to provide a device ci the above nature provided with a rotary switch-operating member, said member bein normally prevented from rotation by a lug projecting from said plunger, said lug being slidably located in a lockingu slot in the bottom edge of a surrounding bracket member.

A further object is to provide a device ci the above nature which will be simple in'construction, inexpensive to manufacture, easy to install and manipulate, compact, and very eiiicient and durable in use.

lVith these and other objects in view there have been disclosed on the accompanyingdrawings two forms in which'the invention may be conveniently embodied in practiceA `Fig. 1 represents a perspective view of the safety switch showing the cover and switch in open position.

Fig. 2 is a fragmentary sectional view the same taken on the line 2-2 of Fig. looking in the direction of the arrows.

Fig. 3 is a perspective detail view of the sliding plunger member for retaining the cover in closed position while the switch is closed and preventing the closing ci the switch while the cover is open.

Fig. 4 is a fragmentary sectional 'view showing the locking plunger and cam plate in locked position, said View being taken along the line 4-4 of Fig. 1,'looking in the direction of the arrows.

Fig. 5 is a fragmentary sectional view simi- 1929. Serial No. 365,957.

lar to Fig. 4 with the cover shown in closed position.

Fig. 6 is a fragmentary sectional view, similar to Fig. 5, of a modied form of the invention ttor use upon a switch of the double throw type.

Referring now to the drawings in which like reference numerals denote corresponding parte throughout the several views, the numeral 10 indicates a casing having a cover l1 hinged thereto at one side thereof. The cover il is provided at one side of its center with an inwardly extend g rivet member i2, on which mounted a ccf ar 13 and a locking disc ifi forming catch, Mounted in the base ci? the casing i() is an insu'ating switch blociaI 15 of usual construction., upon which is mounted standard switch of the single throw type. l

The switch as herein disclosed comprises pair of pivoted switch blades 16 adapted to be swung down into engagement with a corresponding pair of stationary ciip con- Andern"bers i7. The blades 16 are connect together adjacent their upper ends by a rectangular insulating' cross-bar 18 having a vertical hooi; member 19 connected there with, se d member i9 having an inclined siot 2G in its upper edge tor slidably fitting about the base 2i oi a Ushaped switch operating rod, said rod having oli-set horizontal ends 22 and 23 adapted to be journaled in the sides 24; and Q5 respectively of the casing.

The 'front eilt-set end 23 of the rod 21 is reduced in diameter and squared. as shown by the numerai said squared end having nonrotatively mounted thereon a washer 27, a cam plate and a tubular collar member 29, said tnbrn ir collar having a cylindrical reend 30 ittingwitliin an aperi the side 25 of the casing 10. The section 26 extends slightly beyond the reduced section 30 Jfor nonrotativeiy receiving a U-shaped handle-attaching clip member 32, the latter having a square aperture in its base 82a for fitting over the squared end 26 of said shaft. The cti-set portion 23 oit the operating rod is threaded at its extremity, bevond the squared section 28, to receive a nut 33 and a washer 34, as clearly shown in Fig. 2 of the drawings.

In order to rotate the operating rod 21 for opening and closing the switch, provision is made of a handle member having manipulating knob 36 on its outer end, said handle member havin a flattened off-set inner extremity 37 for tting within au aperture 38 in one of the inturned ends 39 ot the clip 32. Provision is also made of a bolt 40 passing through an aperture 41 in the handle 35 at a point spaced from the olf-set extremity 37, said bolt being locked in position by a nut 42 and cotter pin 42a. By means of this construction, the turning of the handle by reason of its non-rotative engagement with the squared end 26 of the operating rod 21 will rotate said operating' rod for closing the switch.

When the cover 11 of the casing is open, the cam plate 28, which is non-rotatively mounted on the shaft 26, lies in engagement with a lug 43 on the lower end of a plunger 44, said plunger being slidably supported b v a tubular bracket 45 having side plates 46 and 47 secured to the front side 25 of the casing as by rivets 48 and 49. The bottom ot the tubular bracket 45 is cut away to provide a locking slot 50 within which the lug 43 will be held against rotation, so long as the cover remains open, by a helical compression spring 51 surrounding the upper part of said plunger 44. The lower part of the spring 51 engages the top of the tubular bracket 45 while the top of said spring is connected to a horizontal laterally-extending flat tail member 52 adapted to interlock with the circular disc 14 on the cover member and prevent the lalltterd` from being opened when the switch is c ose spring 51 when the cover is forced to closed position and causing said tail member 52 to tightly press against said cover 11. The lug 43 of the plunger 44 will then lie below the lockingslot 5() and will no longer obstruct the movement of the cam plate 28. The switch may then be readilysclosed by swinging the handle 35 in a clockwise direction, as viewed in Fig. 1.

To open the switch the handle will be swung in the opposite direction, the rotative action of the spring 51 causing the lug 43 to rotate into alinement with the locking slot 50 in the tubular bracket 45 so that, when the cover is raised, the lug 43 will move upwardly into said slot for locking the switch in open position.

One advantage of the present invention is that the switch may be operated when the cover is open by manually pressing down the plunger, without the use of 'injurious tools.

This is sometimes required fory inspection purposes.

Vhile there have been disclosed in this specification two forms in which the invention may be embodied, it is to be understood that these forms are shown for the purpose of illustration only, and that the invention is not to bev limited to the specific disclosures but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the moditications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired to secure Letters Patent, is:

1. In a safety switch, a casing, a cover hinged to one side of said casing and having a catch depending from the inner surface thereof, a pivoted switch' within said casing, a rotatable operating member for moving said switch to open and to closed positions, a bracket secured within said casing and forming a bearing parallel to one side wall of the latter, a plunger having a cylindrical bod)7 portion slidable and rotatable within said bearing, said plunger having alateral projection at its upper end for interlocking with said catch when said operating member is moved to close said switch.

2. In a safety switch, a casing, a cover hinged to one side of said casing and having a catch, a pivoted switch within said casing, a. rotatable operating member for moving said switch to open and to closed positions, a bracket secured within said casing and having a tubular portion arranged parallel to one side wall of the latter, a plunger having a cylindrical portion movable within the tubular portion of said bracket, said plunger having a lateral projection at its upper end for interlocking with said catch when said operating member is moved to close said switch.

In a safety switch, a casing, a cover hinged to one side of said casing and having a catch, a pivoted switch within said casing, a rotatable operating member for moving said switch to open and to closed positions, a slidable plunger on the edge of said casing, a cam plate on said operating member, a lug on said plunger adapted to lie in alinement with said cam plate when the cover is open for preventing the rotation of said o erating member, and means actuated by t e closing of said cover for retracting said lug for permitting said rotation for closing the switch.

4. In a safety switch, a casing a cover hinged to one side of said casing and having a catch, a. pivoted switch within said casing, a rotatable operating member for moving said switch to open and to closed positions, a spring-pressed slidable plunger on the edge of 'said casing, a cam p ate on said operating member, a lng on said plunger adapted to lie in alinement with said cam plate when the covcr is open for preventing the rotation 'ot said operating member', and means actuated by the closing of said cover for retracting said lug for permitting said rotation tor closingr the switch.

5. In a safety switch, a casing having an opening, a cover for closing said opening and having a catch, a movableswitch within said casing, a rotatable operating rod for moving said switch to open and closed positions, a handle outside of said casing ri gidlv connected with said rod. a tubularbracket secured to the side of said casing and having a locking slot in its lower edge. a rotatable plunger slidable in said tubular bracket and having a lug adapted to tit within said slot,

`said plunger having a latch on its upper end to interlock with said catch.y and means on said operating rod located in alinement with said lug to prevent rotation ot said rod. and means actuated by the closing` ot said cover for depressing said plunger to bring said lug outI of said locking slot. permitting said operatingl -rod to be rotated to close said switch and interlock said catch aud latch.

6. ln a safety switch. a casing having` an opening, a. cover for closing said opening.

said cover having a catch secured to but lspaced from the inner surface thereof. a movable switch within said casina', a bracket secured within said casing and having a tubular portion arranged parallel to one side wall of the latter. a nlun ger slidablv mounted within said tubular portion and having a lateral projection at its upper end normallv located adjacent to butI out ot' alincmcnt with said catch'` means actuated h v the closing ot said switch for rotating said jilunger to bring said lateral projection into alinement with said catch, and means on said plunger for preventing the closing ot said switch while said cover is open.

7. In a safety switch, a casing havingan opening, a cover for closing` said opening. a switch in said casing. a switch-operating member, a bracket secured to a side wall ot said casing and adapted to provide a tubular bearing. a plunger having a cvlindrical portion slidable within said bearing. said bearing having a slot extending upwardly Jfrom the lower end thereof. a lateral projection at the lower' end ot said plunger, and spring means interposed between said plunger and said bracket to bias said projection into in terlocking engagement with the walls ot said slot to Iestraingsaid plunger from rotary movement, said projection also normally having-interlocking engagement with a. movable part of the switch, said cover when closed being adaptedto depress said plunger against the bias of said spring means, whereby said projection is disengaged from the walls of said slot to permit closing movement of said switch.

8. In a safety switch, a casing having an opening, a cover for closing said opening, a switch within said casing, means *for closing said switch, a one-piece metal bracket se cured to the inner surface ot one side wall of said casing, said bracket having an intermediate oiset portion to form with said side wall a substantially tubular bearing, a plunger having an intermediate Cylindrical portion slidable and rotatable within said bearing, said plunger having a lateral projection at the upper end thereof for locking said cover in closed position when said plunger is rotated, said plunger also having a lateral projection at the lower end thereof and lying in the path of said switch-closing means, and means including an integral part of said bracket for normally locking said plunger in agiven angular position, said cover when closed acting directly upon said plunger to unlock the same to thereby permit manual actuation of switch closing means and locking of said cover.

9. In a safety switch, a casing having an opening, a cover for closing said opening, said cover having a disk-shaped catch secured thereto in spaced relation to the inner surface thereof, a switch in said casing, a switch-operating member, a plunger slidably and rotatably mounted upon one side wall of said casing, a coiled torsion spring interposed between a part of said casing and said plunger to bias the treme position and to simultaneously bias the same to a given rotary position, said plunger having a. lateral projection at the upper end thereof, said projection being p0- sitioned adjacent to said catch when the cover is closed and being operable automatically to interlock with said catch when said v -switch is closed, said plunger also having a JOSEPH JOHN DANTE.

latter slidably to its upper ex- 1 

